1. Field of the Invention
The present invention relates generally to the field of semiconductor technology. More particularly, the present invention relates to a method for fabricating a semiconductor device with a strained-silicon structure.
2. Description of the Prior Art
Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, and other electronic equipment, as examples. Semiconductor devices are typically fabricated by sequentially depositing insulating or dielectric layers, conductive layers, and semiconductive layers of material over a semiconductor substrate, and patterning the various material layers using lithography to form circuit components and elements thereon.
Transistors are circuit components or elements that are often formed on semiconductor devices. Many transistors may be formed on a semiconductor device in addition to capacitors, inductors, resistors, diodes, conductive lines, or other elements, depending on the circuit design. A field effect transistor (FET) is one type of transistor.
Generally, a transistor includes a gate stack formed between source and drain regions. The source and drain regions may include strain layers such as epitaxial SiGe layers. Typically, prior to the growth of the epitaxial SiGe layers in the source and drain regions, a SiN hard mask is formed on the spacers of the gate stack. After the growth of the epitaxial SiGe layers, the SiN hard mask is removed. However, SiGe fall-on defects are difficult to be removed by the SiN hard mask removing process.
Therefore, there is a need of providing an improved method for fabricating the semiconductor device to obviate the drawbacks encountered from the prior art.